Pour the apple cider into a medium saucepan and set it over medium heat. Bring it to a boil, then reduce to a simmer, cooking until the liquid reduces by about half, about 15-20 minutes. Set it aside to cool slightly before adding it to the batter.
472 grams apple cider
Preheat your oven to 425°F (218°C). Grease a standard 12-count muffin pan with nonstick spray or line with paper liners. For the tallest muffins, plan to fill every other muffin cup so the heat can circulate evenly.
In a large mixing bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, allspice, and salt until well combined. Set aside.
300 grams all purpose flour, 2 teaspoons baking powder, 2 teaspoons baking soda, 2 teaspoons ground cinnamon, ½ teaspoon ground ginger, ½ teaspoon salt, ½ teaspoon nutmeg
In a separate medium bowl, whisk the oil, granulated sugar, and brown sugar until combined. Add the eggs and vanilla extract, whisking until smooth.
112 grams oil, 100 grams granulated sugar, 100 grams light brown sugar, 2 large eggs, 2 teaspoon vanilla extract
Whisk in the applesauce, sour cream, and cooled reduced apple cider. The mixture should be smooth and well combined.
72 grams unsweetened applesauce, 72 grams sour cream
Pour the wet mixture into the bowl with the dry ingredients. Use a rubber spatula to gently fold the batter together until no streaks of flour remain. Be careful not to overmix, as this can make the muffins tough. The batter will be thick.
Using a large cookie scoop or spoon, divide the batter evenly among every other muffin cup, filling each one all the way to the top.
Bake at 425°F for 5 minutes to give the muffins a tall rise. Without opening the oven, reduce the oven temperature to 350°F (177°C) and continue baking for another 10-15 minutes. The muffins are done when a toothpick inserted in the center comes out clean or with just a few moist crumbs.
Remove the pan from the oven and let the muffins cool in the pan for 5-10 minutes. Then carefully transfer them to a wire rack.
While the muffins are still warm but easy to handle, whisk together cinnamon and sugar in a small bowl. Brush the tops and sides of the muffins with melted butter, then roll or sprinkle with the cinnamon-sugar mixture until fully coated. Serve warm or at room temperature.
4 tablespoons unsalted butter, 100 grams granulated sugar, 1 teaspoon ground cinnamon